Thio-indoxyl derivatives and process of making same.



UNITED STA E s PATENT OFFICE.

KARL ALBRECHT, or BiEBn'IoH,

GERMANY, ASSIGNOR TO THE FIRM (lF-KALLE AND COMPANY, AKTIENGESELLSGHAFT, OF BIEBRIOH;

GERMANY.

THIO -INDOXYL DERIVATIVES AND PROCESS OF MAKING SAME.

I have found that the thioindoxylic car- 'boxylic .acid' (alpha-oxythionaphthene carboxylic acid) or thioindoxyl (alpha-oxythionaphthene), described in the specification of the' French Letters Patent No. 359,398 be united with isatin, forming a new product, having presumably the following constitution:

In the following two examples I give modes of operation for the manufacture of the new product, but I do not wish to be understood as intending to limit myself'to the special methods therein described as the product may be obtained by other methods.

The essence of my invention consists in combining molecular proportions of thioindoxyl or of thioindoxyl .carboxylic acid and isatin. I I

The manner in which the combining of such substances is accomplished can be varied within wide limits, without affecting the principle of my invention. Example I. 15 parts of thioindoxyl (alphaoxythionaphthene) are dissolved in 3000 parts of hot water together with 2.2 parts of calcined soda and then mixed with a solution of 14.7 parts of isatin in 3000 parts of hot water. After boiling for a short time the molecules of thioindoxyl and isatin will have combined with the new product formed. This coloring matter is then filtered off and washed.

Example II. If in the foregoingexample the stated quantity of thioindoxyl (alphaixythionaphthene) be replaced by the equivalent amount 19.4 partsof thioindoxyl carboxylic acid (alpha-oxythhmaphthene carboxylic acid) and the process be carried out as in that example, the same product is obtained.

way carbon dioxid being evolved.

Specification of Letters Patent. Application filed July so. 1906. Serial in. 328.366.

, rcoxidized into the The reaction proceeds in the same Patented Dec. 24, 1907.

In the above given examplesthe thioin- ALBRECHT, l'doxyl, its carboxylic acid as well as the isatin may be replaced by homologues and derivatives of the same. 111 this manner substitution products of the new dyestuffsare obtained. The new coloring matter consists of scarlet red crystalline needles, possessing a metallic luster, which areinsoluble 0r dillicultly soluble in the usual solvents. Concentrated sulfuric acid dissolves it with a brown coloration. When treated with reducing agents, such asalkaline hydrosuliite or sodium suliid, the new coloring matter goes into solution with a light yellow color. The leuko compound, contained lution, has a good allinityfor the textil fibers, which when thus charged with the leuko compound are colored red. on'contact with the atmospheric air or other oxidizing agent, the reduction product being thereby coloring matter. In this manner the new dyestuil' may be utilized for the production of scarlet red the fiber, which are exceptionally fast to all 1 agents.

Now what I claim is:

1. The herein described process of manufacturing a red coloring matter consisting in combining thioindoxyl carboxylic acid with isatin. 2. The herein described process of manufacturing a red coloring matter consisting in combining thioindoxyl with isatin.

3. The new dyestulf, having the following constitution I a metallic luster,

being insoluble or (lillicultly soluble in the usual solvents, soluble in concentrated sulfuric acid with a brown color, and which may be transformed by reduc ng agents into a leuko compound, caable ofbeing reoxidized and prec pitate l as the dyestuil' from its aqueous solution by exposure to air.

In testimony whereof I have signed my l name to two subscribing witnesses.

. KARL ALBRECHT.

l \Vitncsses: I

l JEAN, GRUND,

l CARL GRUND.

this specification in the presence of in this soshades upon 

